Saturday, March 27, 2010

The Data is in on New Zealand's 1st Space Launch

Rocket Lab's January newsletter carried some details of the first data-set obtained from the Nov launch of their first ATEA-1 rocket conducted at Great Mercury Island.

Mindful of the famous one-liner from Big Bang Theory - ".....and this is why Sweden has no space program", back in November, I blogged about the launch of a sounding rocket to see if that constituted the commencement of New Zealand's space program.

Whilst the world contemplates the implications of the Obama administration's cancellation of the Ares V Constellation program, and we consider the pros and cons of Nation/State Vs Private Sponsorship, I thought it would be timely to see what news there is from New Zealand.

Following the Nov 2009 launch of the ATEA-1 (a bio-fuel, low carbon, patented design, sounding rocket), a commercial fishing boat recovered the stage one booster 17 klms offshore recovering a vast array of data that could be analyzed.

The Rocket Lab team reports - "we are still reviewing the data, but initial findings suggest that the booster was providing the expected thrust levels at launch and showing good, stable combustion for the full burn-time, consuming all available fuel. The recovered booster also confirms clean separation of the second stage. Calculations from the raw data obtained confirm that the vehicle was on course for a nominal trajectory to over 100 kilometres altitude".

The newsletter also provides an interesting insight into the nimble, clever design innovations that are achievable from small private space programs that can clearly tap brilliant skill-sets, respond to the actual needs of the market, and come up with scalable and customizable solutions for an expanding customer base.

In particular they are surprisingly open about the features of their Avionics Flight Computer (SRA) - "The unit is physically incredibly small, fitting within an envelope 50mm diameter x 150mm length. The weight of the unit is a mere 250 grams including batteries. The reduction in size and weight of the unit is critical for improving the performance of sounding rockets such as Ä€tea-1. The unit is designed and tested to MIL-109-E shock and vibration tests and can handle up to 80°C ambient temperature.

The hardware consists of a low-power 32-bit microcontroller with RS232 output port and auxiliary expansion ports. It has 16-bit data logging capability, with an in-built Inertial Measurement Unit consisting of 3-axis accelerometers, gyroscopes and magnetometers. Onboard GPS is standard and it is designed to interface with a number of telemetry options including the Iridium satellite network."

I resisted the temptation to photoshop in a blue adult molar - in the words of another Sheldonism (Big Bang Theory) "...everything is better with blue-tooth" and that seems like the only thing that is missing. Perhaps in the executive model?

So AARTScope visitors, we await the next installment of the Rocket Labs success story, or as I like to think of it as - the New Zealand Space program. Clearly there is a much greater role for private space programs and sponsors as NASA maintains is game face in its latest Ares quarterly report.

Thursday, March 18, 2010

V842 Cen observations to support Hubble Cosmic Origins Spectrograph run

V842 Cen first came to attention in 1986 as a Nova and follow up studies by Warner/Woudt published in the journal of physics identified it as exhibiting similar behaviour to GW Lib. Thus both these stars are now the subject of Dr Paula Szkody's study using the cosmic origins spectrograph on the HST.

This observation task was somewhat more difficult than last week's effort as the variable star map coverage is somewhat problematic as there are few comparison stars of similar magnitude. However just 7 arcsecs and 20 arcsecs away are two known catalog stars that were selected for comparitive magnitudes. Which effectively places them close to the annulus/skybackground settings of Photometric measurement tools. At 1.22arcsec per pixel on my trusty FLI that's a tight shot!!!! Normal practice is to try and get the annulus to 2-2.5 times the FWHM of the star. So its tight!

Here at least I was able to adjust the annulus and the inner sky radius such that 0323-0709135 was kept away from the target calculation area. (ie between the two)

The image below I have zoomed in a little to illustrate the difficulty of the task.

One surprise was that the catalog star 0323-0709135 seemed to be a little brighter visually than expected. Instructions from AAVSO alert 418 indicated 0323-0709135 was expected to be slightly fainter than its near neighbor 0323-079110 at 14.88.

Either way V842 Cen appears to be 15.43 at my measurement which I submitted to the AAVSO this morning. I suspect the tightness of the shot and 0323-0709135 sneeking into 0323-0709110's sky background may have V842 Cen a little closer to 0323-0709135's magnitude than it actually is - you can see this in the photo.

Sunday, March 7, 2010

GW Lib data to support Hubble COS mission

One of the delights of being an amateur astronomer is being able to assist real scientists with (hopefully) useful data on various targets that they need to keep an eye on prior to observation runs with toys that I can't afford eg the HST.

An alert (Notice#417) went out this week from the AAVSO requesting data on two cataclysmic variable stars to support Dr Paula Szkody's upcoming spectrograph observations on the Cosmic Origins spectrograph on the HST.

GW Lib is a CV that needs to be fainter than Mag 14 when the mission takes place, and it has been known to infrequently outburst.

AAVSO members regularly fly cover and give early warnings on any unexpected events that may affect the mission integrity.

GW Lib is at DEC -25.00.25 so that immediately eliminates a good number of the world's telescopes. Australia has had large monsoonal lows pushing into the interior of Australia and the weather has been pretty ordinary this week as a result.

My choice of a couple of 300 sec images was a little short in duration as the SNR was a bit low with the moon still being at 55%. I was able to confirm that the target was about Mag 15.39 (given the low SNR maybe a little closer to 16) in the Johnson V filter (untransformed).

I'll try again tonight with a little longer exposure.


UPDATE: 10/03/2010
JD Airmass GW_Lib 147 143 Err SNR
2455265.209 1.11373 15.501 14.422 14.000 0.025 42
2455265.214 1.100 15.421 14.432 13.988 0.031 34
2455265.219 1.08756 15.514 14.422 14.003 0.041 26

Ave 15.479 14.425 13.997 0.032 34


UPDATE: 11/03/2010
Today I tidied up my Sequence a little, deleting 128 and I added 157 to the comp star list as visually it looked to be the identical magnitude to GW Lib. I also stacked the three images with a median combine to give a much much stronger SNR. With the SNR of a number of the comp stars now being over 100 (preferred) the Magnitude of 147 was almost identical to the chart magnitude listed in AAVSO chart 2084CCS. Comfortable with the improvement in accuracy GW Lib magnitude was measured at 15.629 (Johnson V untransformed).

Note the stronger SNR of the target now at 60 with the comp star's SNR >100.

Seven AAVSO members contributed observations and Dr Paula was pleased to hand the observations to the Hubble space controllers this morning who then gave the go-ahead for tonights UV run on the Cosmic Origins spectrograph.

Congrats to Dr Paula, hope everything goes well tonight! It all starts again on the 14th as the next COS run is on V842 Cen.


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