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...