Sunday, January 31, 2010

Wild Card

Water vapor in the lower stratosphere plays an important role in the radiative balance of the atmosphere. This excellent paper by Solomon et al. (2010) reports on recent trends and changes in stratospheric water vapor levels and the relationship between water in the stratosphere and surface temperature. The processes that determine stratospheric water vapor levels, including rockets and aircraft combustion emissions, are poorly understood and so water vapor could be a climate change wild card.

Sunday, January 24, 2010

S200 Static Test Success

India successfully static tested the S200, a new large solid rocket motor (SRM) that will power India's GSLV Mark III launch vehicle. Each S200 will burn 200 tons of SRM propellant, 85% of the Ariane V SRMs. SRM emissions are perhaps the most harmful of all propellant types to stratospheric ozone, though scientists do not have sufficient data or models to prove this assertion. The importance of the S200 test and imminent GSLV Mark III deployment is to suggest that SRM emissions - and so ozone impacts from rocket launches - may increase in coming years.

Thursday, January 21, 2010

"What Might Have Been" Thursdays

ROMBUS. Reusable Orbital Module Booster and Utility Shuttle. Massive. A Single Stage To Orbit (SSTO) launch vehicle from the mid-1960s, when SSTO seemed possible. We now know that the numbers don't work out very well for the SSTO concept, though there are still true believers. Engineers argue endlessly about SSTO possibilities. Rombus, featuring drop away liquid hydrogen tanks, would have emitted about 4 kilotons of water vapor into the middle atmosphere each launch. The ROMBUS mesospheric contrails would have been spectacular, perhaps lasting for days.

Tuesday, January 19, 2010

Shuttle Contrail in Mesosphere

The science is pretty clear on this, though I have not seen a paper on this particular cloud. The mesopause is so cold and the Shuttle emits so much water vapor that contrails form at about 85 km altitude. At least occasionally. This sort of very high altitude cloud is usually only found near the polar summer mesopause. Is it important that rockets can cause these mesospheric clouds to form at midlatitudes? Do mesospheric rocket contrails say anything about climate?

Sunday, January 17, 2010

Commercial Spaceflight Federation

Nice website for the interesting Commercial Spaceflight Federation. The CSF carries some influence in Washington. Its mission is (in part) to "promote the development of commercial human spaceflight, pursue ever higher levels of safety, and share best practices and expertise throughout the industry."

It looks like the CSF might act in a manner something like the International Air Transport Association, which has a mission for commercial aircraft flight. The IATA's mission is (in part) "improved safety is IATA’s number one priority, and IATA’s goal is to continually improve safety standards." That is similar to the CSF. But they go on to say "Another main concern is to minimize the impact of air transport on the environment."

Thursday, January 14, 2010

"What Might Have Been" Thursdays

The Boeing 2707. "Two seven oh seven". It sounds as cool as it looks. The hydrocarbon fueled 2707 supersonic transport would have cruised at Mach 2.7 at an altitude of 20 kilometers, well above the mid-latitude tropopause. Boeing had 115 airframe orders on the books when congress cancelled development in 1971. Will supersonic transport ever be viable? What does "viable" mean when speaking of the stratosphere?

Monday, January 11, 2010

Soot Plume

This is look-back cam on a Delta II showing soot plume from RS-27A kerosene fueled rocket engine. That plume looks like pretty weak sauce. But it appears that rocket engines emit a few hundred times more soot (per unit mass of kerosene burned) than aircraft engines emit. Is it a big deal?

Sunday, January 10, 2010

You Could Not Make This Up

No kidding this is an actual plume from, we understand, a Russian military rocket that failed last month one hundred or so kilometers up. It is also possible that it was a test of some method to foil missile defense sensors. I don't know. It is a mesmerizing pattern, whatever happened. It is easy to predict that this plume modified the ionosphere in some way.

Saturday, January 9, 2010

The Inscrutable Hand of Ms. Market

It has been suggested that the demand for transportation services has a "trough" around 3 hours so that supersonic transport is not profitable. But people will pay a big premium to get people and material across the planet in 90 minutes. Maybe so. Ms. Market's take might look like this. If this is true, it has significant implications for climate and ozone. And good news for Virgin Galactic.

Monday, January 4, 2010

Nitrous Hybrid Rockets Are All The Rage

See here for big conference of users. What do hybrids emit? How would 1000 launches per year of hybrid rockets affect climate and ozone? We don't know.

Saturday, January 2, 2010

This Vehicle Would be a Large Emitter

Big plans perhaps. Follow the "12 to 1" rule : 12 kilotons into the stratosphere for every kiloton into LEO. That would be over 2 kilotons per launch.