RV-X

[Lar]

I thought it was a lot worse than that... that most SSTO end up with negative payload fractions unless built with large quantities of unobtainium...

BUT if 66% is achievable(which I doubt), it might not be a bad idea to pursue this... NewSpace are teaching us that it's about cost, primarily, and a bigger rocket isn't necessarily more expensive in the long run

You have it backwards. That's a 66% (up to 71%) loss in payload over for a VTO SSTO Vs a VTO TSTO.

No I don't. I am saying a 66% loss is impressive and I doubt, based on nothing at all (IANARS), it's achievable. I would expect negative mass fractions or maybe a 98% loss or some such.

a 66% loss (in a fuel rich architecture) means that such a vehicle is worth pursueing.

[russianhalo117]

there was a topic on this issue on this site, but it get deleted because of our ultra intelligent moderation team. i am sure they were testing this type of vehicle since 2009. there was even a twitter-account dedicated to it in japanese. nihonjin friends were translating it time to time. anyone remember?

You mean this thread of RV-X's predecessor called RVT: https://forum.nasaspaceflight.com/index.php?topic=19571.0

The twitter handle for the RVT related engine tests seems to have gone dark circa 2015

https://twitter.com/spacelark_jaxa

There was an interesting rumor that Mr Inatani, who was heavily involved with RVT work, is an advisor for Canon Electronics Inc. in some capacity, and that they were somehow involved with the avionics for the next RVT vehicle despite the MHI lead...

Mr Inatani also seems to have connection to SS-520-4 launch failure and the upcoming SS-520-5 launch attempt of which Canon Electronics Inc. is a part of along with JAXA's ISAS.

[Always out of base]

This is the latest status of RV-X and CALLISTO.
http://www.jaxa.jp/press/2018/08/files/20180802_CALLOSTO.pdf
RV-X; Test flight until 2019 Mar at Noshiro Rocket Testing Center
CALLISTO; Test flight in 2020 at Guiana Space Centre

[Asteroza]

This is the latest status of RV-X and CALLISTO.
http://www.jaxa.jp/press/2018/08/files/20180802_CALLOSTO.pdf
RV-X; Test flight until 2019 Mar at Noshiro Rocket Testing Center
CALLISTO; Test flight in 2020 at Guiana Space Centre

This starts to explain some of the stuff about JAXA/Prof Ishitani being involved with Callisto.

It seems the current plan is to fly by the end of 2018 RV-X to 100m, and send results data to ESA to inform Callisto development, with JAXA getting Callisto data back.

Didn't think RV-X was that far along, but if the PDF images are any indication, the test vehicle assembly is pretty far along.


It's pretty telling that JAXA/ESA feel so compelled to demonstrate capabilities equivalent to Falcon 9 first stage. They are now in a race between chinese efforts and Blue Origin to get an operational reusable first stage. Though Callisto is more immediately usable as a booster, but RV-X is LOx/LH2 which makes it poorly suited for booster/first stage work.

[Asteroza]

There was a MHI puff piece on Ars, which mentioned RV-X indirectly.

https://arstechnica.com/science/2018/11/long-on-tradition-japan-grapples-with-a-rapidly-changing-rocket-industry/

If you ignore the article closing on a dig about japanese inequality, there are some interesting nuggets from the MHI press junket. Notably they are trying to get H-3 down in price to compete with Falcon 9 (though that presupposes Falcon-9 not getting any cheaper, nor the looming specter of BFR/BFS), and a 8/year flight rate (which would make for a tightly packed schedule since the fisherman cooperatives effectively close Tangashima for half the year).

There is a sense that the gutting of the GEO market due to the new megaconstellations caught MHI flatfooted as they were too far along on H-3 work. There is the implication that a H-3 follow-on is going to try to happen, though linguistically it's not clear if this is a (semi)reusable variant of H-3 or a clean sheet design. There is serious work being done on RV-X to feed into Callisto and vice versa, as the fear of SpaceX getting too far ahead on reusability is felt as real. This might suggest Callisto might not be exclusively an ESA affair, and perhaps may form the basis of something greater.

I would normally speculate this might imply JAXA/ESA Arianspace/MHI joint work on a Callisto based new reusable vehicle as a cost share, but both ESA and JAXA currently have a heavy emphasis on "domestic" assured access to space, which would go against such a partnership in theory.

[Steven Pietrobon]

I would normally speculate this might imply JAXA/ESA Arianspace/MHI joint work on a Callisto based new reusable vehicle as a cost share, but both ESA and JAXA currently have a heavy emphasis on "domestic" assured access to space, which would go against such a partnership in theory.

Perhaps they could share production of the reusable first stage, while each country makes their own second stage. Once a production run of first stages is made (say 10 for each country plus spares), you shouldn't need to rely on other countries.

[ChrisWilson68]

I would normally speculate this might imply JAXA/ESA Arianspace/MHI joint work on a Callisto based new reusable vehicle as a cost share, but both ESA and JAXA currently have a heavy emphasis on "domestic" assured access to space, which would go against such a partnership in theory.

Perhaps they could share production of the reusable first stage, while each country makes their own second stage. Once a production run of first stages is made (say 10 for each country plus spares), you shouldn't need to rely on other countries.

They could also just share costs on development and then build two factories to build the same booster.

[Asteroza]

They could also just share costs on development and then build two factories to build the same booster.

That's a beautiful thought, but has anyone done that recently? Even allegedly license built copies of aircraft always end up " customizing" some aspect (usually avionics) to give some work to a domestic supplier, usually with enough changes that end up creating an incompatibility between base and license built variants.

Say something "simple" like the choice of wiring spec (say ESA preferring spacewire for instance) for wiring up things has substantial downstream impacts.

[su27k]

Here's an interesting twitter thread about history of Japanese reusable rocket research, by Matt Richardson who is getting a PhD in aerospace engineering in Japan. It includes some info about RV-X and its predecessor RV-T.

[tyrred]

Perhaps a relevant video, courtesy of TMRO:

[FutureSpaceTourist]

Article says this is a precursor to Callisto flights in 2022

JAXA to start flight tests in June to develop reusable rocket tech
KYODO NEWS KYODO NEWS - Mar 7, 2020 - 15:38

TOKYO - The Japan Aerospace Exploration Agency will begin flight tests in June to develop technology for the reuse of the first stages of launch vehicles, a government source said Saturday.

https://english.kyodonews.net/news/2020/03/af113ab23c61-jaxa-to-start-flight-tests-in-june-to-develop-reusable-rocket-tech.html

[Steven Pietrobon]

There were two static fires of RV-X, RV-X-1 and RV-X-2 in the late 2010s. I'm not sure what the current status is. Seems like JAXA have switched their interest to the ATRIUM engine; a combined cycle air breathing and rocket engine using hydrolox. There are two vehicles planned. A single ATRIUM engine version called FTB for 2024 and a triple ATRIUM engine version for 2027. If anyone can provide Japanese translations of the slides used in the video, that would be much appreciated!

[Mahurora]

There were two static fires of RV-X, RV-X-1 and RV-X-2 in the late 2010s. I'm not sure what the current status is. Seems like JAXA have switched their interest to the ATRIUM engine; a combined cycle air breathing and rocket engine using hydrolox. There are two vehicles planned. A single ATRIUM engine version called FTB for 2024 and a triple ATRIUM engine version for 2027. If anyone can provide Japanese translations of the slides used in the video, that would be much appreciated!

I'll give you some quick bits on what I think is important on the slides.

First slide:
height 7m, dry mass 2t, take off mass 2.9t, engine thrust 4t
2 stage flight test - first stage is 100m low altitude hop to test landing capabilities. second stage test will reach 5k altitude and will also demonstrate flight guidance.

third slide: "staged development plan for continous vehicle manufacturing" (below each stages are underlying technologies listed)
1st stage - engine R&D (reference engine)
2nd stage - small scale FTB flight test
3rd stage - atmospheric assist reusable sounding rocket development

fourth slide: small scale FTB review
above left - risk management for various individual components and technologies
below left - vehicle system fuel/hydraulics flow schematic
right - weight distribution, from above: structure 310kg, propulsion and attitude control bogie 240kg, on board electronics 110kg (around 500W power consumption anticipated), engine system 210kg

fifth slide: future space transportation visions starting from small scale flight demonstration
it basically shows technology maturation roadmap, scale-up plan. Ultimately they aim for the white LV, a multi-stage space shuttle with short launch-down time and high payload.

[Mahurora]

More on the "third stage development" vehicle (reusable observation rocket) from the third slide :

100kg payload to over 100km (the ISAS presentation mentions over 150km)
reusability goal - over 100 launches
Hydrolox
Usability goals - less than 24h from launch to re-launch
13.5m, 4.1t dry, 11t launch mass, 4 * 40kN motors, throttleable to 40% max thrust.

from @chageimgur on twitter and MHI paper (再使用型ロケット開発に向けた技術実証 Challenge for the Space Transportation Cost Reduction by Reusable Launch Vehicle)

[Mahurora]

Btw, RV-X test flight was scheduled for March of 2022 by September of 2021. That was a minor delay compared to the end of 2021 goal but now even that delayed schedule wasn't kept and was further delayed. I wasn't able to find any concrete current first flight schedule though. Chief of Noshiro Rocket Test Facility Kobayashi Hiroaki, where RV-X will be tested, mentions that the engine tests were continuing and they've had various issues regarding the engine though are getting things fixed and in place. They're still preparing for first flight he mentions. (From January 2023 issue of ISAS news)

[Mahurora]

https://twitter.com/ZplusC1Bst/status/1703019991132783076

Some insights from a JAXA seminar held at Kakudachu Center from last year.

Reason RV-X uses a Hydrolox engine : because Japan has the most experience with Hydrolox
Difficulties that led to RV-X delays : LH2 leaks

[Mahurora]

RV-X maiden flight has once more been postponed to 2025 due to issues concerning safety procedures.

[TheKutKu]

https://x.com/JAXA_NTC/status/1859801478237446644
https://x.com/JAXA_NTC/status/1860346971283947969

Umbilical test

[jstrotha0975]

I thought they cancelled this program?

[Mahurora]

Never was.