Reentry prize?

Pete Lynn wrote:

I am not sure if reentry and landing can really be separated and pursued
in isolation, too many unnatural distortions.

My proposal is not separating reentry and landing. You have to get a payload
from orbital velocity and orbital altitude to zero velocity and zero
altitude without cooking or breaking it. That includes both reentry and
soft landing.

Also, you do not want to
be paying for launches, if you do have to pay for this, it should be
another prize, two birds one stone.

?

Other than the obvious follow ons from the X-Prize, another launch prize
system I have contemplated is the development of a 10kg class launch
vehicle. Say $10 million distributed equally among the number of
successful launches each year.

I like your idea. But I would not call that a prize, but a limited market
guarantee.

I would expect most groups to purchase high altitude air launches off
some external group, White Knight for example, though I expect there are
far cheaper alternatives. There are significant advantages in high
altitude launches at this scale, though this would obviously be a choice
left to the individuals.

Yes, I agree that high altitude/low speed staging is very promising for
small payloads. For large (as in saturn V class) payloads VTVL is the way
to go.

Have you been working on the newest design from Len Cormier? It looks
similar to something you have proposed a few years ago.

I would also expect a great deal of
commonality in the various components used by various groups, in effect
groups might set themselves up as developers and suppliers of various
components to all the competing groups, engines for example, might
effectively become OTS.

Such a prize might almost be within the grasp of small hobby type
groups, and all approaches from MCD to SSTO could be tested in the
market place at the lowest possible cost. The 10kg constraint is
required so as to maximize flight rate. Groups might launch larger
vehicles than this, but only be paid at this rate.

Once there was a degree of design convergence, and the market had proven
itself you might then move on to a larger payload prize system. Though
I expect this would not be required as the market and technologies would
by then be sufficiently developed that larger commercial interests would
takeover.

Pete.

I like the idea. This would be a good thing for NASA or DARPA to offer.

But I think the followon for the X-Prize has got to be a manned. The X-Prize
would never have generated that much excitement if it were a much more
ambitious unmanned mission.

Derek Lyons wrote:

Ruediger Klaehn wrote:
Drop tests are surely somewhat cheap and funny, but they don't tell
much about how the vehicle is able to withstand reentry...

Of course not. Reentry can not be simulated that easily. But it tells
something about the ability of the group to build a working autonomous
vehicle.

That can be determined by fairly simple ground tests, no need for
something as silly as the drop testing. (Especially considering that
any serious team will have already done that testing.)

For simple yet heavy approaches that use a parachute, drop testing will not
be a significant hurdle. Most teams should be able to design a reliable
parachute release mechanism and wire it to a barometer or a GPS unit.

But for the more exotic approaches such as parawings, rotary-style powered
rotors, inflatables, lifting bodies etc. the drop test will be a good test.

And if landing from a few km is so trivial, why has NASA spent years doing
drop tests for the X34, X38 and X43 etc?

The DARPA Grand
Challenge was a joke because the set a specification well beyond that
what was reasonably achievable and on a timeline much shorter than
anything approaching rational. Then they ran the test *anyhow*, and
produced what amounted to a massive no-test at great expense and
complication.

I disagree. The grand challenge was a good investment even if nobody won it
this time. A race is much more exciting for the teams than some tests. The
grand challenge even spawned a private robot racing league. So DARPA will
definitely get some decent ROI.

They have been trying the traditional approach of giving contractors
achievable goals and lots of money for more than a decade, and have not
much to show for it.

The red team vehicle has driven several hundred miles autonomously before
the race, so there was a chance that they would reach the goal. In fact the
reason they have lost is probably that they overestimated the other teams
and therefore went so fast that they drifted out of a curve.

The problem is much less complicated than with satellites or warheads. You
don't need to put the RVs in a precise orbit in a precise orientation.

ROTFL. Yes, you *do* need a fairly precise orbit, unless dropping
RV's in the wrong place entirely is something you find desirable. ( I
assure you that your insurance company doesn't.) Furthermore, without
a reasonably precise trajectory you cannot predict (in advance) that
each RV will experience a trajectory that creates the desired test
environment.

You will have a very large landing area anyway, since the reentry properties
of the RVs are different: Some will use lifting reentry, others will use
ballistic reentry, still others will use inflatable or unfoldable high area
heat shields to brake high up in the atmosphere and so on.

So if the separation mechanism adds or subtracts 10m/s from the velocity of
the launcher it won't make much difference as far as the target area is
concerned.

You have a fairly precise trajectory before separation, so adding some small
random velocity by the separation mechanism will not let the capsules land
on a different continent or something.

Rand Simberg wrote:

[snip]

It depends on whether the purpose of the prize is to develop TPS
materials, or entry vehicles. The latter would be more useful, but
more complex.

The idea was definitely to permit very exotic designs such as hypersonic
drogue chutes, inflatable or unfoldable heat shields and so on. Prizes make
most sense where there are unorthodox approaches to be explored.

But for the people who want to try something more traditional it might have
some merit to have a simple capsule body as a baseline design that people
could, but would not have to, use.

Everyone who wants to try something exotic would have to have the same
attachment points and center of gravity as the capsule.

Derek Lyons wrote:
Ruediger Klaehn wrote:
I never said that building a wooden heat shield is cheap or simple. In fact
it is probably quite expensive with western labor costs since it requires a
lot of manual labor for assembly and quality control.

But it is still a low-tech approach compared to almost anything else that
has been suggested for heat shields.

Commonly 'low-tech' is interpreted to mean 'cheap and simple'. If
it's *not* cheap and simple, then the technology level is essentially
irrelevant.

This is a complete nonsense interpretation for low vs high tech.


D.

--
Sander

+++ Out of cheese error +++

Ruediger Klaehn wrote in message ...
Pete Lynn wrote:

....snip...

I would expect most groups to purchase high altitude air launches off
some external group, White Knight for example, though I expect there are
far cheaper alternatives. There are significant advantages in high
altitude launches at this scale, though this would obviously be a choice
left to the individuals.

Yes, I agree that high altitude/low speed staging is very promising for
small payloads. For large (as in saturn V class) payloads VTVL is the way
to go.

Have you been working on the newest design from Len Cormier? It looks
similar to something you have proposed a few years ago.

Yes indeed, the concept is in part inspired by inputs from
Pete and Robert Lynn--as implied by the credit to Peter Lynn
Kites on the title page of our presentation at SAS 2004.
There's still a lot of updating needed on our web site;
however, the SAS 2004 presentation: Space Van 2008, a kite-
assisted SSTO is now posted on http://www.tour2space.com

Best regards,
Len (Cormier)
PanAero, Inc.
(change x to len)
http://www.tour2space.com

"Ruediger Klaehn" wrote in message
...
Pete Lynn wrote:

I am not sure if reentry and landing can really be separated and
pursued in isolation, too many unnatural distortions.

My proposal is not separating reentry and landing. You have to
get a payload from orbital velocity and orbital altitude to zero
velocity and zero altitude without cooking or breaking it. That
includes both reentry and soft landing.

Actually I meant this in the greater context, I am not sure that you
would want to separate such reentry testing from that of the launch
vehicle. The design of one effects the other to perhaps too great an
extent. The excessive tendency to try to compartmentalize out of
complexity generally results in good detailed design but bad overall
design, which is currently the more critical. This is something the
space industry is particularly noted for and the reason often attributed
for the failure to achieve CATS.

Also, you do not want to be paying for launches, if you do
have to pay for this, it should be another prize, two birds one
stone.

?

If prizes are better than direct payments, for example the X-Prize, then
it would be cheaper and more productive to use a separate prize to
accomplish this launch task than to pay for it directly.

Other than the obvious follow ons from the X-Prize, another
launch prize system I have contemplated is the development of
a 10kg class launch vehicle. Say $10 million distributed
equally among the number of successful launches each year.

I like your idea. But I would not call that a prize, but a limited
market guarantee.

I would expect most groups to purchase high altitude air
launches off some external group, White Knight for example,
though I expect there are far cheaper alternatives. There are
significant advantages in high altitude launches at this scale,
though this would obviously be a choice left to the individuals.

Yes, I agree that high altitude/low speed staging is very
promising for small payloads. For large (as in saturn V class)
payloads VTVL is the way to go.

Yes

Have you been working on the newest design from Len
Cormier? It looks similar to something you have proposed a few
years ago.

We have talked... and I like where Len has taken it. It seems to me
this approach reduces the big problems to nice bite sized portions
enabling use of existing hardware and technology, with healthy margins,
and without compromising overall utility and performance. Functionally
it is largely the equivalent of a fully reusable SSTO without all the
hard work and expense. Further, it is not an all or nothing solution,
there are multiple fall back positions and opportunities to make a few
bucks on the side from early on in the development, this might greatly
ease financing constraints.

I would also expect a great deal of commonality in the various
components used by various groups, in effect groups might set
themselves up as developers and suppliers of various
components to all the competing groups, engines for example,
might effectively become OTS.

Such a prize might almost be within the grasp of small hobby
type groups, and all approaches from MCD to SSTO could
be tested in the market place at the lowest possible cost. The
10kg constraint is required so as to maximize flight rate.
Groups might launch larger vehicles than this, but only be paid
at this rate.

Once there was a degree of design convergence, and the
market had proven itself you might then move on to a larger
payload prize system. Though I expect this would not be
required as the market and technologies would by then be
sufficiently developed that larger commercial interests would
takeover.

I like the idea. This would be a good thing for NASA or
DARPA to offer.

But I think the followon for the X-Prize has got to be a manned.
The X-Prize would never have generated that much excitement if
it were a much more ambitious unmanned mission.

Agreed, as stated above. Though I would say that of the many groups
going for the X-Prize only one seems on track to get it in the given
time. Ideally it could have been a competition in space between many
groups, unfortunately few have developed actual vehicles.

I fear the all or nothing prize structure does not encourage the ongoing
depth and diversity of industry required for a serious crack at CATS. I
think we need more groups developing more commercial hardware at lower
costs, we need a highly competitive ongoing industry for which every day
is a new race. The market needs to be more integral to the process such
that entry barriers to commercial sustainability are lowered.


Pete.

(Derek Lyons) wrote in message ...
Commonly 'low-tech' is interpreted to mean 'cheap and simple'. If
it's *not* cheap and simple, then the technology level is essentially
irrelevant.
You mean building pyramids was high tech, yes?

Stefan

D.

(Len) wrote in message . com...
Ruediger Klaehn wrote in message news:c7ctt2$2d7g3
....
Have you been working on the newest design from Len Cormier? It looks
similar to something you have proposed a few years ago.

Yes indeed, the concept is in part inspired by inputs from
Pete and Robert Lynn--as implied by the credit to Peter Lynn
Kites on the title page of our presentation at SAS 2004.
There's still a lot of updating needed on our web site;
however, the SAS 2004 presentation: Space Van 2008, a kite-
assisted SSTO is now posted on http://www.tour2space.com

Thanks, I have been waiting eagerly for that presentation to go
online.

I was wondering if the use of dual fuels on the orbiter (LH2+Kerosene)
is essential to this concept. Would it be possible to keep the liftoff
rocket on the kite gondola and use only hydrogen on the orbiter?

If you go through the trouble of handling LH2 anyway it would seem to
make sense to go for the higher Isp and avoid having multiple types of
engines and fuels on board a single vehicle. Was it the density of
kerosene? The unreasonable number of RL10s required to get enough
thrust with hydrogen?

Oren

(Stefan Dobrev) wrote:

(Derek Lyons) wrote in message news:
Commonly 'low-tech' is interpreted to mean 'cheap and simple'. If
it's *not* cheap and simple, then the technology level is essentially
irrelevant.

You mean building pyramids was high tech, yes?

The only possible ways to interpret what I said as meaning that is to
be on drugs or lacking a forebrain.

D.
--
Touch-twice life. Eat. Drink. Laugh.

On Fri, 07 May 2004 05:30:27 -0700, Stefan Dobrev wrote:

(Derek Lyons) wrote in message
...
Commonly 'low-tech' is interpreted to mean 'cheap and simple'. If it's
*not* cheap and simple, then the technology level is essentially
irrelevant.
You mean building pyramids was high tech, yes?

snip

At the time, the pyramids were very high tech requiring skills, knowledge,
and of course, sophisticated organization that most of humanity couldn't
manage. And obviously they weren't cheap and simple.


Karl Hallowell