A satellite spends years in a cleanroom and a few minutes on a rocket. In between, it spends days on a truck, in a cargo hold and on a loading dock, and that is the part of its life nobody photographs. It is also the part where a surprising number of spacecraft pick up the damage, contamination or humidity that shows up later as a failed test at the launch site. The container that carries it is not packaging. It is the last piece of ground support equipment the satellite ever uses. 🛰️
We have built several of these containers for European customers, for small satellites, payloads and sensitive subsystems, and every one of them started from the same idea: a Peli-Hardigg single lid case used in reverse application. Instead of a deep base and a shallow lid, you pick a case with a shallow base and a deep lid. The satellite is mounted on its cradle in the base, which never moves, and the deep lid is lifted straight up and off, by a small crane, a gantry hoist or, on the smaller sizes, two people. The satellite is then exposed on a stable, flat platform at working height, exactly as it would be on a bench, and nothing has to be lifted out of a box.
This article explains why that geometry works, what the industry expects from a satellite transport container, what the Peli-Hardigg single lid range offers as a starting point, which options and part numbers matter, and where the limits of a rotomoulded case are. It is written for the people who actually have to ship the thing: integration engineers, AIT managers, project logisticians and the procurement officer who has to justify the invoice.
What a satellite transport container has to do
The requirements are consistent across the industry, from the largest geostationary spacecraft to a 6U CubeSat, and only the scale changes. Container specialists such as Beyond Gravity describe the job as protecting the spacecraft during road, air and storage with dynamic damping, thermal control and filtering, and they list the parameters their containers monitor: temperature, humidity, acceleration and pressure, with a target of roughly 19 to 25 °C and below 65 percent relative humidity while the container is in use (Beyond Gravity, Satellite Containers). A US patent for a modular satellite container for the 150 to 600 kg class lists the same functions: vibration isolation, a positive-pressure nitrogen purge to keep the interior clean and dry, and monitoring, and notes that general-purpose electronics containers do not provide enough of any of them (US 6,237,795).
Boiled down, a container has to provide five things:
- A stable mechanical interface. The satellite bolts to a cradle or adapter plate through its own lifting or launch-adapter interface; it never rests on foam alone.
- Shock and vibration isolation. The cradle is isolated from the shell by elastomeric mounts or wire-rope isolators tuned to the mass, so that road vibration and handling shocks are attenuated before they reach the structure.
- A clean, dry, sealed volume. The satellite is bagged in cleanroom film, often double bagged with desiccant and a nitrogen purge inside the inner bag, as launch brokers such as Spaceflight describe in their own shipping guidance (Spaceflight, Transporting Your Satellite to the Launch Site), and the container around it is sealed and, where needed, purged and slightly pressurised.
- Pressure and humidity management. Air freight means altitude cycles; a container needs a valve that equalises pressure without admitting moisture, and an indicator that tells you the desiccant is still working.
- Evidence. Shock recorders or indicators on the container, and increasingly on the cradle, so that the receiving team knows what the hardware experienced. The Lockheed Martin space packaging standard, for example, specifies where ShockWatch indicators go and notes the common trigger thresholds of 25, 50 and 75 g (LMSSC Packaging Standard P-134).
Large spacecraft get bespoke composite or aluminium containers with air conditioning, turnover fixtures and doors, built by specialist firms over months. Small satellites, subsystems, optical payloads and instruments do not have that budget or that lead time, and this is the gap a properly configured Peli-Hardigg single lid container fills.
The 10 things we learned
1. Reverse application is the whole trick 🔁
A Peli-Hardigg single lid case is a one-piece rotomoulded polyethylene shell split into a base and a lid, and the part number tells you the depth of each. AL2624-0803 is a case with a 26 by 24 inch interior footprint, an 8 inch deep base and a 3 inch deep lid: a normal box. AL2624-0824AC is the same footprint with an 8 inch base and a 24 inch lid. Turn that thinking around and you have a satellite container: the shallow base becomes the transport platform, the deep lid becomes the cover. The catalogue is full of these shallow-base, deep-lid combinations, from AL2221-0419 with a 4 inch base and a 20 inch lid, through AL3428-0625 and AL4141-0846, up to AL5834-0140FT with a base only 41 mm deep under a lid over a metre tall, and fork pockets moulded in.
The reason this matters is operational. In a conventional box the satellite has to be lifted out over the rim, which means a crane, a spreader and a risky vertical move with the lid in the way. In reverse application the lid comes off upward, the satellite stays put on a flat base at bench height, and the AIT team can inspect, connect and purge without a second lift. Reinstall the lid, close the latches, and the spacecraft is sealed again. On our smaller builds two technicians lift the lid by its handles; on larger ones a light hoist takes it in one movement.
2. The shell is a proven starting point, not a compromise 🧱
Single lid containers have been the standard military and aerospace transit case for decades, with more than 500 sizes, moulded in the United States and the United Kingdom. Peli describes the construction plainly: resin powder is rotated in a heated mould so that 15 to 20 percent more material accumulates in the corners and edges, where drops land; hardware is recessed so it cannot be sheared off; anti-shear blocks around the rim keep the lid aligned to the base under impact; and a double-walled tongue-and-groove rim carries a gasket that stays sealed after a knock. Options include IP67 sealing, and the Advanced Case Solutions catalogue lists the certifications that can be applied by design: ATA Spec 300 Category 1 for air transport, MIL-STD-810 and Def Stan 81-41 Level J, with test reports available. The facilities are ISO 9001:2015 certified and the products are NATO codified, which matters when the customer is an agency or a defence prime.
This is the point for procurement: the shell arrives with an aerospace pedigree, and what we add is the interior and the fittings. We explain how the same family serves European defence programmes in why Peli cases fit EU SAFE projects.
3. The satellite rides on a cradle, and the cradle rides on isolators 🧲
Foam alone is not a satellite interior. Foam is excellent at spreading a drop across a large area and useless at holding a 60 kg structure at a defined attitude for a thousand kilometres of motorway. Every container we have built uses a metal cradle or adapter plate that picks up the satellite's own interface, usually the launch adapter ring, the lifting points or a set of threaded inserts on the base plate, so that the spacecraft is held exactly as it is held during testing.
The cradle is then mounted to the base of the case through elastomeric shock mounts, which Peli's Advanced Case Solutions engineers size to the mass and the g-limit; the ACS catalogue quotes isolation of impacts up to 15 g using shock mounts and foam bumpers. The gap between cradle and shell, the sway space, is what allows the isolators to work, and it is why the container is always larger than the satellite. Peli-Hardigg's European engineering offices in Germany, Spain and France handle the design, from CAD layout and g-force mapping to prototyping and, where the customer requires it, drop, vibration, leak, heat and dust testing in Peli's own lab.
4. Cleanliness is a process, and the case is the last barrier 🧼
Nothing about a polyethylene case is cleanroom-grade, and nothing needs to be, because the satellite does not touch it. The sequence that works, and that the industry uses at every scale, is: satellite bagged in antistatic cleanroom film inside the cleanroom, desiccant and often a low-rate nitrogen purge inside the bag, a second outer bag, and only then into the container. NASA describes the same logic at the top of the scale, where transport containers are pre-cleaned, flooded with dry nitrogen and held at slight overpressure before the spacecraft enters (NASA, Cleanroom Tech Key to Success in Space).
What the container adds is a sealed, gasketed volume that stops dust, water and salt air reaching the bags, and a surface that can be wiped down before it enters a cleanroom airlock. We specify a light interior colour on satellite builds for exactly that reason: you can see contamination on a grey or white interior, not on a black one. Peli's single lid colour chart includes grey, tan, white and a range of others; the Light Lift series comes in fewer colours but the same greys and whites.
5. Pressure, humidity and the two small parts that matter most 💧
An aircraft hold cycles pressure on every flight. A sealed container with no valve either bulges and strains its gasket on climb or clamps shut on descent, and both are bad for a seal that is supposed to keep water vapour out for the next fortnight on a launch-site apron. Two options from the accessories list do most of the environmental work:
- The pressure relief or purge valve. Standard or mil-spec purge valves equalise pressure without letting moisture in. On builds where the customer purges with nitrogen, the valve becomes the purge point, and we fit an inlet and a bleed on opposite ends of the case so that the volume is actually swept.
- The humidity indicator. A window in the shell that reads 20, 30 and 40 percent relative humidity at a glance, so that a technician can check the desiccant on the apron without opening anything. Paired with a desiccant chamber, it is the cheapest insurance in the whole build.
The rest of the environmental story is thermal, and a rotomoulded shell is a good insulator but not a climate-control system. For satellites that must be held near room temperature, the usual additions are an off-the-shelf temperature and humidity logger inside the sway space and, where transport runs through extremes, external insulation or a climate-controlled vehicle. Below about 60 kg of spacecraft this is usually enough; above it, the container conversation starts to include active heating and cooling and moves into the territory of the dedicated container builders.
Large Peli Protector cases for ground support equipment
6. Handling hardware decides whether the container is used or cursed 🏗️
The lid comes off upward, so the lid needs somewhere to attach a hoist. Peli's option list includes lifting rings and tie-down rings, and we fit lifting rings to the lid on anything above a size two people can manage. The base needs to move as a unit with the satellite on it, so it gets forklift provision, either the moulded-in skid runners and forklift bash plates of the FT variants or a bolt-on pallet, and tie-down rings so that it can be lashed in a truck or an aircraft pallet. Edge casters, moulded in on the W variants or bolted on, let the base roll across a hangar floor without a forklift.
Latches on the deep lid are the all-catch configuration, which the part number marks as AC: latches on all four sides, so that the lid seats evenly on the gasket and cannot be popped on one edge by a side impact. Lockable padlock hasps or a cable catch give the customs seal somewhere to go. The hinged lid with cable stay is the one option we do not use on satellite builds, for the obvious reason that the lid has to come off completely.
7. The base must survive being set down badly 🪨
The failure mode that nobody plans for is the apron: the base, satellite on top, is set down by a forklift onto an uneven surface or dropped the last few centimetres. The single lid construction helps here, with its thicker corners and moulded stacking ribs that give the base a flat, rigid floor, and the shock mounts under the cradle do the rest. What we add is a bash plate on fork-truckable bases and, on the largest, a steel subframe. Where a customer needs certification, the container goes through Peli's test lab for the drop, vibration and leak sequence and comes back with a report that the launch provider can accept.
8. Record what happened, or you will argue about it 📈
Shock indicators and shock loggers are not something we supply; they are standard, off-the-shelf items from several manufacturers, and we recommend that every customer fits both and tells us where they want them mounted. The indicator, a single-use tri-axial label such as a ShockWatch on the outside of the case, is for the handler: a visible red window at 25 or 50 g tells everyone on the dock that this box has a story. The logger, a small battery-powered recorder with a three-axis accelerometer and usually temperature and humidity sensors, is for the engineers, and it belongs on the cradle rather than on the shell, because the shell and the shock mounts attenuate what reaches the satellite; a logger on the outside records what the box experienced, a logger on the cradle records what the spacecraft experienced. It gives a time-stamped record that the receiving AIT team can compare against the satellite's qualification levels before deciding whether a retest is needed. We provide the mounting points on the cradle and a cable or bracket route on request. It is inexpensive relative to the container, it is standard practice in the space packaging specifications, and it turns a dispute into a data review.
9. Light Lift changes the arithmetic for air freight ✈️
Peli-Hardigg's Light Lift series takes the same rotomoulded design and cuts around 30 percent of the weight, aimed at two- and four-person carries with a gross payload up to 136 kg. For a small satellite container that flies commercially, and most do, the difference between a 20 kg and a 14 kg lid is real money on every leg and a real difference in whether two people can handle the lid without a hoist. The catalogue marks Light Lift variants with an LW suffix; AL2624-0505LW, for instance, weighs 8.9 kg against 12.7 kg for the standard shell. We specify Light Lift where the payload is under about 50 kg and the container flies; standard weight where it goes by road with a forklift at each end and the extra mass is free protection.
10. Know where the rotomoulded case stops 🚧
Honesty is part of the brief. A single lid container in reverse application is the right answer for CubeSats, small satellites, optical payloads, instruments, antennas and subsystems up to a size where two people or a small hoist can lift the lid and a forklift can move the base. It is not the right answer for a two-tonne telecommunications spacecraft that needs a pressurised, air-conditioned container with a turnover fixture and a door; that is the domain of the specialist container builders, and we say so when a customer asks. Peli's own single lid guarantee is a one-year limited warranty on the moulded shell with 90 days on hardware, which is the industry norm for engineered transit cases and different from the lifetime guarantee on the Protector range; customers should know both numbers before they sign.
Which single lid cases work in reverse application
A short selection from the catalogue of shallow-base, deep-lid combinations that we start from. Dimensions are approximate interior figures from Peli's own tables; the sway space and the cradle decide how much satellite actually fits.
| Part number | Interior L x W (mm) | Base depth | Lid depth | Empty weight | Typical use |
|---|---|---|---|---|---|
| AL1616-1812AC/HL | 400 x 403 | 464 mm | 309 mm | 12.2 kg | Conventional orientation for a 3U to 6U CubeSat in its own bag; lid on handles |
| AL2221-0419DE | 572 x 535 | 102 mm | 498 mm | 14.5 kg | Reverse application, 12U to 16U class or an instrument on a plate |
| AL2624-0824AC/HL | 662 x 610 | 205 mm | 610 mm | 20.6 kg | Reverse application, small satellite on a cradle, two-person lid |
| AL3428-0625AC/HL | 864 x 699 | 155 mm | 630 mm | 25.9 kg | Reverse application, microsatellite or deployable antenna, hoist on lid |
| AL4141-0846AC | 1041 x 1041 | 211 mm | 1156 mm | 59.9 kg | Reverse application, tall payload standing upright, crane on lid, forklift under base |
| AL5834-0140FT/AC | 1480 x 870 | 41 mm | 1016 mm | 60.8 kg | Reverse application, fork-truckable base, the closest thing to a purpose-built satellite container in the standard range |
AC marks all-catch latching, HL a handle on the lid, FT a fork-truckable base, DE stacking ribs matched to Classic racks, W moulded-in edge casters and LW the Light Lift version. The full list runs to more than five hundred sizes, and Peli builds custom moulds for programmes that need them.
How a build goes, step by step
- Interface drawing. We start from the satellite's mechanical interface control document: mass, centre of gravity, lifting points, adapter ring, keep-out zones, and the g-limits the structure is qualified to.
- Case selection. Footprint plus sway space on all sides decides the interior size; the satellite's height in transport attitude decides lid depth; handling at both ends decides base options, forklift provision, casters, weight class.
- Cradle and isolation design. Peli's ACS engineers or our partners design the plate or cradle, pick the isolators and confirm the natural frequency sits well away from truck and aircraft excitation.
- Environmental fit-out. Purge valve or valves, humidity indicator, desiccant chamber, interior colour, gasket specification, and mounting provision for the customer's own shock or climate logger if one is used.
- Handling hardware. Lifting rings on the lid, tie-downs on the base, hasps for seals, ID plate and stencilling.
- Test and documentation. Where required, drop, vibration, leak and dust testing in Peli's lab with a report; otherwise a fit check with the flight-representative structure and a handling rehearsal with the customer's crew.
- Delivery with the procedure. A one-page handling and purge procedure travels with the container, because the people opening it at the launch site are rarely the people who closed it.
For the electronic ground support equipment that travels alongside the satellite, checkout racks, power supplies and telemetry gear, the answer is a shock-mounted rack case rather than a single lid container; we cover that configuration in how rack cases turn IT hardware into fly-away kits. Smaller items such as harnesses, tools and MGSE fittings go in standard Protector cases with cut foam; the interior options are in foam, dividers or TrekPak, and what IP67 actually promises is in waterproof, water-resistant or submersible.
Shock-mounted rack cases for EGSE and ground stations
Frequently asked questions
What is reverse application on a Peli-Hardigg single lid case?
Choosing a case with a shallow base and a deep lid and using the base as the transport platform. The payload is mounted on a cradle in the base and the deep lid is lifted off upward, so the payload is never lifted out of a box.
Can a satellite really travel in a polyethylene case?
Small satellites, payloads and subsystems do, routinely. The satellite is bagged and purged inside the cleanroom, mounted on an isolated cradle, and the sealed case keeps dust, water and handling shocks away from the bags. Large spacecraft need pressurised, climate-controlled containers, which is a different product.
How is the lid lifted?
By hand on the smaller sizes, using the lid handles; by a light hoist, gantry or small crane on larger sizes, using lifting rings fitted to the lid. The base is moved by forklift or on casters.
Which certifications can the container carry?
Depending on the design, IP67 sealing, ATA Spec 300 Category 1, MIL-STD-810 and Def Stan 81-41 Level J, with test reports from Peli's lab. Peli's facilities are ISO 9001:2015 certified and the cases are NATO codified.
How do you keep the satellite dry?
Desiccant and, where specified, a nitrogen purge inside the bags; a gasketed shell with a pressure equalisation or purge valve; a humidity indicator in the shell and a desiccant chamber; and, if the customer wants a record, an off-the-shelf temperature and humidity logger inside the sway space.
Do you supply shock recorders?
No. Shock indicators and loggers are standard products available from several manufacturers, and customers normally already have a preferred type. We recommend fitting an indicator on the outside of the case and a logger on the cradle, and we provide the mounting points for them.
What does the guarantee cover?
Peli's single lid containers carry a one-year limited guarantee on the moulded shell and 90 days on hardware, which is the norm for engineered transit cases. The custom interior is covered under the terms of the build.
What is the lead time?
Standard shells are catalogue items; the cradle, isolation and fit-out are engineered per programme. Ask early, ideally when the interface control document is frozen, and the container is ready before the satellite is. Use the contact form with the mass, dimensions and interface of the payload and we will come back with a proposal.
The short version
A satellite transport container has to hold the spacecraft on its own interface, isolate it from shock and vibration, keep it clean and dry through pressure cycles, and record what happened on the way. For small satellites and payloads, a Peli-Hardigg single lid case in reverse application, shallow base under the cradle, deep lid lifted off by hoist or hand, with shock mounts, purge valve, humidity indicator, lifting rings and forklift provision, does all of that with a shell that already carries the aerospace certifications. Above a certain size, it hands over to the dedicated container builders, and we will tell you where that line is. 🌍
