Intuitive Machines Terrestrial Return Vehicle (TRV)

[RanulfC]

Must be a lot of old MIRV bodies out there already, just aching to be turned into mini Space Clippers. Putin would wet himself, though...

Different requirements. MIRVs want to penetrate deep into the atmosphere without slowing down, but this is supposed to glide slowly to a landing, slowing down high in the atmosphere.

Interesting point - I always assumed that terminal velocity would be relatively slow for MIRVs, high subsonic or thereabouts, which isn't too different to an object that's 'flying' to a landing (I say 'flying' because most returning vehicles fly in exactly the way which a brick doesn't (to quote Douglas Adams, almost)).

Supersonic nominally... If they get down to "subsonic" speeds they should have hit the ground already and they aren't actually (mostly) designed to do that at all And most MIRVs have those nasty toxic hypergol thrusters and pretty crappy L/D (little lift) so they don't (and aren't designed to) manuever after entry.

Modern version of the film bucket?

Yes, that seems like it would be very relevant experience.  How did the spy satellite film return systems handle reentry?  Was it guided return or just ballistic?  What sort of TPS did they have?  How big was the parachute and when did it open?

Very ballistic with pretty much no terminal guidance and a lot of "luck" to be in the right area for an air-snatch. TPS was simple ablative and the parachute opened once the package was low supersonic (drouge) followed by subsonic main parachtute deployment so as to allow maxium time for the grab manuever.

Randy

[Steven Pietrobon]

I couldn't find a thread on this. Here's their web page where they give a couple of videos.

https://intuitivemachines.com/Aerospace/trv/

The page says October 2016 for the launch, but I'm not sure if that was a mistake and they were referring to their 12 October 2015 drop tests.

[Burninate]

With this design philosophy we at Intuitive Machines are able to move from concept to first launch of the TRV within 24 months. Follow our progress through our first successful launch in October 2016.

Very nice to see someone take a path I suggested for Dream Chaser-scale vehicles - blunt-bodied gliding reentry followed by steered parafoil decent & landing.

[TrevorMonty]

Great post Steven.

While this is designed for return of small payloads eg experiment results.. With all the smallsat LVs eg Electron, Firefly in development, an upgraded version of the TRV maybe able to deliver small payloads to ISS for <$10m. It also has potential as freeflier for these small LVs, send it up to LEO for a few hours or days and return.

Somebody from CASIS said Biotechnology industry would make greater use of ISS if they could send and return stuff on demand.

[arachnitect]

This is the JEM airlock launched vehicle we saw earlier?

http://forum.nasaspaceflight.com/index.php?topic=35879.0

[Asteroza]

Great for scenarios where you have a lot of upmass in a single delivery, but want distributed time sensitive return of payload. But are these going to be stored inside ISS, or stowed on an external rack and brought in when needed?

[TrevorMonty]

They are costly to deliver, every cubic metre the TLV takes up in Cygnus is a cubic metre of pressurized cargo that can't be delivered. The Dragons trunk could handle a few, but more often than not the trunk has payloads these days.

[Asteroza]

The thought crossed my mind that the Intuitive Machines TRV as a cargo return vehicle is great for time limited cargo (living samples), but the fact that it fits through the JEM airlock got me thinking that a TRV derivative with a matching upper stage service module, designed for launch on the various smallsat launchers cropping up, might make for good business.

Currently, the TRV has a payload bay, parafoil, and cold gas thrusters with tankage. What if you reduced the cold gas storage to something minimal (anti-spin) and increased the payload bay but kept the outer mold line? Pair it with a specific upper stage/service module designed to be rematable with this TRV derivative. The matching upper stage would be grapplable by ISS on close approach, then pseudo-berthed to the JEM porch where it can get power to keep warm. JEM arm grabs the TRV and stuffs it into the JEM airlock for unloading/loading and then sends it back out to mate with the upperstage again, then the ISS arm tosses it overboard, where it does it's reentry burn then lets go of the TRV for reentry.

So you get to have ISS upmass for pressurized small cargo (possibly time sensitive), an upper stage/cargo service module with rough rendezvous capabilities, and an upper stage that can do one way delivery to ISS (Nanoracks style small external experiments on ISS)(and limited disposal capability as well). That, and conventional microsat delivery to other orbits.

Now the kicker is the upper stage needs rendezvous capability, so at a minimum, probably cold nitrogen gas thrusters. The current crop of cargo vehicles use hydrazine though, but none normally get close to the JEM porch. If ISS approach limitations for JEM prevent using propellants that can contaminate experiments, then the propellant choices are fairly limited.  The terrible idea I had is nitrogen for propellant, with cold gas vernier thrusters, and a nitrogen electric thruster (resistojet, arcjet, HDLT, EPT?) run on batteries when going up to ISS (assuming a fast approach single orbit rendezvous so some help from the booster). When coming back down, use the ISS recharged battery, and if feasible, an electrodynamic tether in generator/brake mode to power the electric thruster in a higher power mode.



Though if the intent is ISS specific (rather than TRV plus generic upper stage/service module that could be used for conventional smallsat missions), one could argue a rear door single integrated capsule design similar to early Kliper designs, with an arm removable presurized cannister that fits the maxmimum airlock dimensions would be better. Even better would be a porch mount extension to drop the porch lower to provide unimpeded access to the airlock, place a berthing mechanism on the airlock, then berth small cargo capsules directly, but that's something JAXA probably won't go for since that's a rather large remodeling job. That, and the new commercial crew berthing interfaces may be more suitable for a rear docking small cargo craft if it's built similar to single body Kliper designs.

[jongoff]

They are costly to deliver, every cubic metre the TLV takes up in Cygnus is a cubic metre of pressurized cargo that can't be delivered. The Dragons trunk could handle a few, but more often than not the trunk has payloads these days.

Bringing stuff in and out of the ISS is currently pretty time consuming, isn't it? Pretty much have to do an EVA unless it's small enough to go in through the JEM airlock? Eventually NanoRacks has their airlock they're developing that could make that easier, but bringing stuff in-and-out isn't currently very easy.

~Jon

[TrevorMonty]

Use a disposable service module which separates once TRV is with in range of ISS. TRV handles final approach with ISS, while SM deorbits itself.

[Asteroza]

They are costly to deliver, every cubic metre the TLV takes up in Cygnus is a cubic metre of pressurized cargo that can't be delivered. The Dragons trunk could handle a few, but more often than not the trunk has payloads these days.

Bringing stuff in and out of the ISS is currently pretty time consuming, isn't it? Pretty much have to do an EVA unless it's small enough to go in through the JEM airlock? Eventually NanoRacks has their airlock they're developing that could make that easier, but bringing stuff in-and-out isn't currently very easy.

~Jon

Is the NanoRacks airlock being designed primarily for ejection of payloads though? I could see the argument for a berthing/docking interface for small reusable delivery capsules that can ride the new smallsat launchers, in the vein of the IDA interface for commercial crew. Airlock with an external hard stand/grapple/mount for visiting service modules to sit idle and receive power while an airlock passable container or a capsule like the TRV gets passed inside, while unitary capsules can berth directly on the airlock after being grabbed by an arm...

Is there anything like the IDA for small delivery capsules? The JEM airlock can take 576x830x800 mm objects but I guess the short dimension is due to the slide table obstructing considering the square outer hatch. Would the JEM airlock payload dimensions be a defacto standard for small payloads then?