RV-X

[lucspace]

As reported on http://danielmarin.naukas.com/2018/01/10/rv-x-un-prototipo-de-cohete-reutilizable-japones/, Mitsubishi Heavy Industries and JAXA are developing a DC-X-like test vehicle.

[john smith 19]

As reported on http://danielmarin.naukas.com/2018/01/10/rv-x-un-prototipo-de-cohete-reutilizable-japones/, Mitsubishi Heavy Industries and JAXA are developing a DC-X-like test vehicle.

Interesting site. Google translate seems to handle it quite well.

It does in deed look like a smaller DC-X (with 4x roughly 11Klb engines replacing the RL10's) , and flies a roughly similar flight path.

People forget 3 things about DC-X
1) It was built by SDIO, IE customer driven, not supplier driven design.
2) It's core mission was to evolve a design for rapid and complete deployment of a space based ABM system, at least the sensor packages for it.
3) SDIO were OK with a nose first entry because they had an ICBM warehead development background.

If you wanted to run the process in reverse, tuning up an ICBM warehead design from a reusable test vehicle, this would be the sort of shape you'd want.

Who has had an argumentative neigbor recently overfly their territory with a rocket designed to carry a nuclear weapon?

[Kansan52]

The part about the OOEX is intriguing.

[ChrisWilson68]

It's a step in the right direction.  I'd prefer to see more commitment to this direction and more resources put toward it, but at least it's something in the right direction.

[Bob Shaw]

Isn't it nice to see rockets which look like Heinlein & Co intended?!?

[Kosmos2001]

Interesting site. Google translate seems to handle it quite well.

It is one of the best sites about space and stuff in Spanish language. The articles are always a great reading.

[john smith 19]

Isn't it nice to see rockets which look like Heinlein & Co intended?!?

Unfortunately all those spiffy VTOL SSTO designs IRL come with a 66-71% reduction in payload over a VTO TSTO design.

If people are OK with that then game on.

[TrevorMonty]

This test bed vehicle, production RLV could look totally different. At least Japan and Europe are starting down RLV path even if it is only test bed vehicles.

[ellerdrop]

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?

[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

[Lar]

Isn't it nice to see rockets which look like Heinlein & Co intended?!?

Unfortunately all those spiffy VTOL SSTO designs IRL come with a 66-71% reduction in payload over a VTO TSTO design.

If people are OK with that then game on.

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

[ellerdrop]

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

it was RVT but it was talked in 2013, i guess. and as i said there waas a dedicated twitter acoount to it. but i don't remember MHI's involvement

[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

it was RVT but it was talked in 2013, i guess. and as i said there waas a dedicated twitter acoount to it. but i don't remember MHI's involvement

MHI I think was responsible for engines.

[Steven Pietrobon]

I did a study on SSTO a while back. My conclusion was that it was possible, provided you didn't use hydrolox due to its low impulse density. Just about any propellant combination (except hydrolox) worked, but kerolox gave the best performance using non-exotic propellants. Unfortunately, the Japanese are using hydrolox, probably due that to being the only low thrust engine they have. Changing to methalox would considerably improve performance though. Link to my paper below.

http://www.sworld.com.au/steven/pub/nsto.pdf

[Lars-J]

I did a study on SSTO a while back. My conclusion was that it was possible, provided you didn't use hydrolox due to its low impulse density. Just about any propellant combination (except hydrolox) worked, but kerolox gave the best performance using non-exotic propellants. Unfortunately, the Japanese are using hydrolox, probably due that to being the only low thrust engine they have. Changing to methalox would considerably improve performance though. Link to my paper below.

http://www.sworld.com.au/steven/pub/nsto.pdf

Interesting! When did you write this paper? And what might be different in your proposal if you wrote it today?

[pnetmon]

http://www.mhi.com/company/technology/review/Vol.54No.4/abstracte-54-4-33.html
Mitsubishi Heavy Industries Technical Review Vol. 54 No. 4 (December 2017)
Technology Demonstration for the Development of Reusable Launch Vehicle
jp http://www.mhi.com/company/technology/review/pdf/544/544038.pdf
RV-X - Reusable Vehicle - eXperiment


http://www.mhi.com/company/technology/review/Vol.51No.4/abstracte-51-4-21.html
Mitsubishi Heavy Industries Technical Review Vol. 51 No. 4 (2014)
Status of Research and Development Activities on Reusable Launch Vehicle
jp http://www.mhi.com/company/technology/review/pdf/514/514044.pdf

[john smith 19]

I did a study on SSTO a while back. My conclusion was that it was possible, provided you didn't use hydrolox due to its low impulse density. Just about any propellant combination (except hydrolox) worked, but kerolox gave the best performance using non-exotic propellants. Unfortunately, the Japanese are using hydrolox, probably due that to being the only low thrust engine they have. Changing to methalox would considerably improve performance though. Link to my paper below.

http://www.sworld.com.au/steven/pub/nsto.pdf

I can't get a connection to your server.

Are you talking about VTO SSTO, VTHL SSTO or HTHL SSTO?
IIRC you did a propellant study that reckoned Propyne was pretty good but I'm surprised peopled don't factor in changing MR during the ascent, trading instantaneous Isp for being able to lose mass faster by burning off more of the denser propellant (usually the oxidizer if it's LOX or HTP).
That trick, applied to the Saturn V was responsible for 50% of the mass increase to LLO over the life of the programme (and it only applied to the 2nd and ED stages).

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.

Roughly speaking TSTO payload fraction is 3-3.5% of GTOW. Historically SSTO designs (all VTO AFAIK) have settled for delivering about 1% of GTOW. Shuttle was novel in that the 55 000 lb in the payload bay was about 1.4% of GTOW of the stack. So a not SSTO semi RLV with a near SSTO payload fraction. But very impressive for the budget. 

There is only one known SSTO design that does not compromise and aims to deliver full VTO TSTO performance. Everything else seems to be more or less modeled on Philip Bono's proposals (although probably without the Beryllium alloys at 200x the cost of Aluminum) with low aspect ratios and LH2 as fuel.

[Steven Pietrobon]

Interesting! When did you write this paper?

I wrote that in 1998. Gee, how time flies. That was 20 years ago! I presented this at the IAC in Melbourne and then had it published in JBIS.

And what might be different in your proposal if you wrote it today?

I think about that quite often. If I was the "Big Man" in charge of my own space company, it would be a vertical landing first stage using 98% HTP/Syntin with seven 2.5 MN staged combustion engines. Stage structure would be carbon fibre. This results in a compact stage that will have zero problems due to cryogenic propellants. Liftoff thrust would be 17.5 MN.

For the second stage I'm still trying to decide between vertical or horizontal entry and either using hydrolox or methalox, although my current preference is vertical landing using hydrolox. For vertical entry the heat shield would have five holes with deployable doors. Engine nozzles extend to allow operation at both sea level and vacuum for best performance while also reducing interstage height. To increase heat shield area, eight "petals" would attach at base and extend for re-entry. Disadvantage is that mechanical complexity is quite high but eliminates need for header tanks and main loads are only vertical. Due to cryogenic temperatures I would used Al-Li for the tanks and composites for other structures. As a starting point, there would be five 250 kN hydrolox staged combustion (or expander if that is feasible) engines. I chose hydrolox as it gives 20% better performance than methalox and as the second stage is small, the overall dry mass increase is small. The Moon also has abundant oxygen, so the greater 5.5:1 mixture ratio of hydrolox compared to 3.5:1 for methalox and the greater performance of hydrolox means that much less fuel is required from the Earth. Another advantage of vertical is that it makes it easier for launch abort of crewed missions.

If the above gets me 30 t to LEO that would be great. With on-orbit refuelling, Lunar and Mars can be done using on-orbit refuelling and with full reusability! The smaller size of the vehicle with 12 engines should also be much cheaper for commercial missions than the 37 engined behemoth from you-know-who. :-)

[Steven Pietrobon]

I can't get a connection to your server.

Ahh, you must be from a European country! For some reason my website keeps getting black balled by certain European countries (I'm pointing my finger at you Germany!). Can you let me know which country you are from so that I can get the problem fixed? PM me if you want to keep that private. In the mean time, I've attached the paper.

Are you talking about VTO SSTO, VTHL SSTO or HTHL SSTO?

My paper was on VTHL.

[Asteroza]

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...

[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.

[Elmar Moelzer]

I could swear that Jaxa had a similar (though initially smaller program) in the late 90ies. Not sure what happened with it. It did a few hops with a conical vehicle.

[russianhalo117]

I could swear that Jaxa had a similar (though initially smaller program) in the late 90ies. Not sure what happened with it. It did a few hops with a conical vehicle.

I dont know but a different project:
https://space.skyrocket.de/doc_lau/himes.htm

[scientist]

I could swear that Jaxa had a similar (though initially smaller program) in the late 90ies. Not sure what happened with it. It did a few hops with a conical vehicle.

RVT: https://en.wikipedia.org/wiki/Reusable_Vehicle_Testing

[Elmar Moelzer]

I could swear that Jaxa had a similar (though initially smaller program) in the late 90ies. Not sure what happened with it. It did a few hops with a conical vehicle.

RVT: https://en.wikipedia.org/wiki/Reusable_Vehicle_Testing

Yep! That was the one!

https://www.isas.jaxa.jp/e/snews/2001/06_01.shtml

[TheKutKu]

Static fire of RV-X happened at 06:46 UTC Aug 28

[Steven Pietrobon]

The static fire occurred at 21:35 in the video.

[TheKutKu]

https://news.web.nhk/newsweb/na/na-k10015009391000

An engine combustion test for an experimental reusable rocket being developed by JAXA (the Japan Aerospace Exploration Agency) was conducted at a test site in Noshiro City, Akita Prefecture, with the engine burning for over 40 seconds to obtain the necessary data.

JAXA is currently researching and developing a reusable rocket that can be recovered and reused after launch, and plans to conduct a takeoff and landing flight test of the experimental vehicle, named "RV-X," within this fiscal year.

The experimental vehicle is approximately 7.3 meters tall and 1.8 meters in diameter, with a conical fuselage equipped with a liquid-fuel engine and four landing gears to enable takeoff and landing while maintaining a vertical attitude.

On the 20th, the final verification test before the flight test was conducted at the test site in Noshiro City, Akita Prefecture. When the engine was ignited with the vehicle fixed to the ground, a roaring sound was heard and combustion gases rose up.

According to JAXA, the engine burned for over 40 seconds during the test to obtain the necessary data.

The flight tests, scheduled for later this fiscal year [Q1 2026], will involve ascent of the vehicle to an altitude of about 10 meters and confirmation of its ability to land at a designated location. JAXA's Chief Experiment Officer, Takashi Ito, said, "This is an experimental vehicle to obtain basic technology in case Japan decides to develop a reusable rocket in the future. We have finally come this far since we began development around 2016. We would like to continue preparations for the flight tests."