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AAWSAP DIRD, Space Access: Where We’ve Been and Where We Could Go, March 2010

U.S. Department of War · 2010-03-08 · 56 pages · text from the file's own layer

This Defense Intelligence Reference Document, dated 8 March 2010, was prepared by the Defense Intelligence Agency's Defense Warning Office under the Advanced Aerospace Weapon System Applications Program. It is one of a series of advanced technology reports. It surveys the history of space access concepts, covering hypersonic gliders, air-breathing and rocket propulsion, materials, launch options and operating costs. The report argues that reliable, schedulable access to low Earth orbit is mainly a hardware and organizational problem rather than a technology problem.

From the source:Release of 2026-09-18 Incident: 3/8/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD is a historical and conceptual survey of space access systems, contending that the main barrier to routine access to space is a failure to build durable, reliable, operational hardware and the supporting infrastructure needed for regular service to and from low Earth orbit. The report reviews earlier launch and aerospace concepts, especially reusable and aircraft-like approaches, and suggests that U.S. space access development became too strongly centered on expendable rockets derived from ballistic missiles rather than bespoke systems designed for repeated space access and payload delivery. Its central claim is that meaningful future progress will depend on creating a purpose-built space transportation infrastructure, including frequent round-trip capability and orbital support networks, rather than continuing to rely on one-off launch vehicles. Overall, the document presents a forceful case for infrastructure-first space development, though its characterization of past technological choices is more assertive than a fully neutral account of past U.S. space programming.

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UNCLASSIFIED/ /POI\ 8PPl@lsTd:. Ulili Otl! Y
the u Tube, or uperrube, is somewhat conrrovcrsial.
According co the inventor (Patenl o. 6,132,823) and to
claims by the company and their quoted rcsul of rescs
conducred by ranfurd Research lnslirute, it reportedly
has an effective thermal conductivicy of the order of J0
co J00 times grearer than cha of conventional liquid-va
por heat pipes, and over 30,000 tim char fan equiva
lemly sized solid rod of silver. Repons cited also have
indicated puzzling temperature di tribtttions n. o ur
with these rubes unlike conventional thermal condu -
cor and liquid-vapor heat pip . 11,e tube al o app ar
to h ve the ability co function at v ry high re.mperatures,
even up ro the melting point of the material used, nd
ro supporrvery high heat .Auxes. ur cesrs to dare sup
port the high tempera.cure capabilities in addition co
the high thermal conductivities. However, the thermal
ondu ivity is so high chac accurately measuring the
value i very difficult. We have ther fore acquired nine
10' long uperrubes, 5/16" in diameter, and have er up
a method for decermining the thermal conductivity us
ing high heat flux, a water cooled ca.lorimcte.r, and a rake
of over 30 carefully ca.librared thermistor . Thi appara•
tus should provide an accurate means of d rermining the
thermal conductivity, and will also allow us 10 1eck the
high heat flux capabiliiy of ch rube and co po •
ible puzzling rempe.rarure di rributions.
Figure 17 shows a data sec in which the ccmpe cure
across the length of a 1O' long cube hear.ed rom the end
and cooled in air is essenrially connanr, wh r s similar
si.ze copper tube would have the tcmpe cure djsuibu
tion shown in the bocrom curve. Increasing the th rmaJ
conductivicy, k, of che copper by fuctors fr m I 000 to
30,000 shows agreement becween the analysis and the
daca ar 30,000 times chat of the copper, akhough chi is
only a lower limit on the actual condu tiviry. Increas
ing the fucror even more do s nor produ ea di mibl
cllange in the curve relative to the data. We have also
tried ocher methods to estimate the high th rmal con
ductivities we have measured, such the lngenhouss
rechniq_ue; these results also indicate very high th rmal
conductivities. However, we needed a more accurate
mean than previous tests with free conv ion o led
rubes with thermocouples, and therefor d ·sed the
rest appararus shown in Figure I .
The 10 fr Superrubes are heaced by three 2kW oil
rs. Power for the heaters comes from a -ph 2
:\mps.
output power concroUer with two I gs fu ed at 20
For saf-ccy reasons the pow r contr0l1cr and fus
placed in an endosure along with a Watmode" power
meter. A water calorimeter is used ro measure the h~
conducred along rhe Supertube. Fins, hown in Figu
19, are necessary ro transfer the high heal Bux ro d1e
warer; these were fabricaced in such a way that they can
be easily auaclled to the uperrub using hos clamps.
A1 o the fin design increases turbulence in the flow
through the heat exchanger. Having the turbulent Aow
increases the heat transfer rate inro the warer, and also
di ourages boiling, which could oc ur with rJ1e high
heat .Auxes used.
CnlA l•111ptealb2: Dt£ribulon Afon;Qu l'11oeaidCClflPII' f1,1blful
0111• U. t:S.oi ec,..- and 'ID,,2045 tvptl'l:11
,a-------------
, - -~- --r-- -r----r--r---,
:( ,c l3 u ll
• :.t..1-;a__,__,_,,
~°!Altl"l
.:....... On
~tk.-•e.u...,m
X ""'
--c:i..-:.....mi-:_,_..,._____..,,..
~,-c...-.. tC'
Figure 17. Compari.Jon of&enrially Co,uwu Superrube
Tt:mperarure Dfrtribution with 1heort:ticai Dutribution
for a Standard Copper Tithe and Rod. Showing that the
7herma/. Conductivity Must be at Len.st 30,000 limts that
ofCopper.
Figure 18. Fxperimmra/. Appararusfor 10 ft Qu Super
tubes.
UNCLASSIFIED/ /FOR OfifilCl.t.k Wlili 9rtLlf
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Official release, from the pursue collection. The PDF is mirrored here; the original link is above. 56 pages are in the text index: search them above, or from the library's search.