The balloon-borne instrument TELIS (TErahertz and submillimetre LImb Sounder) is a three-channel superconducting heterodyne spectrometer for atmospheric research use. It detects spectral emission lines of stratospheric trace gases that have their rotational transitions at THz frequencies. One of the channels is based on the superconducting integrated receiver (SIR) technology. We demonstrate for the first time the capabilities of the SIR technology for heterodyne spectroscopy in general, and atmospheric limb sounding in particular. We also show that the application of SIR technology is not limited to laboratory environments, but that it is well suited for remote operation under harsh environmental conditions. Within a SIR the main components needed for a superconducting heterodyne receiver such as a superconductor-insulator-superconductor (SIS) mixer with a quasi-optical antenna, a flux-flow oscillator (FFO) as the local oscillator, and a harmonic mixer to phase lock the FFO are integrated on a single chip. Light weight and low power consumption combined with broadband operation and nearly quantum limited sensitivity make the SIR a perfect candidate for use in future airborne and space-borne missions. The noise temperature of the SIR was measured to be as low as 120 K, with an intermediate frequency band of 4-8 GHz in double-sideband operation. The spectral resolution is well below 1 MHz, confirmed by our measurements. Remote control of the SIR under flight conditions has been demonstrated in a successful balloon flight in Kiruna, Sweden. The sensor and instrument design are presented, as well as the preliminary science results from the first flight.

We observed bound levels of the IЈ state in H 2 and D 2 , confined in the outer well of the lowest 1 ⌸ g adiabatic potential close to its (1sϩ2p) dissociation limit, with an equilibrium internuclear distance of Ϸ8 a.u. Rovibronic levels (vϭ0 -2, Jϭ1 -5 for H 2 and vϭ0 -5, Jϭ1 -6 for D 2 ) are populated with pulsed lasers in resonance enhanced XUVϩIR ͑extreme ultravioletϩinfrared͒ excitation, and probed by a third laser pulse. Level energies are measured with an accuracy of Ϸ0.03 cm Ϫ1 , and are in reasonable agreement with predictions from ab initio calculations in adiabatic approximation; the smallness of ⌳-doublet splitting indicating that nonadiabatic interactions with 1 ⌺ g ϩ states are generally weak. Additional resonances are observed close to the nϭ2 dissociation limit, some of which can be assigned as high vibrational levels of the EF 1 ⌺ g ϩ state.

This Guaranteed Time Key Programme, approved by the European Space Agency, aims at determining the distribution, the evolution and the origin of water in Mars, the Outer Planets, Titan, Enceladus and Comets, using the three Herschel instruments HIFI, PACS and SPIRE. It addresses the broad topic of water and its isotopologues in planetary and cometary atmospheres. The nature of cometary activity and the thermodynamics of cometary comae will be investigated by studying water excitation in a sample of comets. The D/H ratio, the key parameter for constraining the origin and evolution of Solar System species, will be measured for the first time in a Jupiter-family comet. A comparison with existing and new measurements of D/H in Oort-cloud comets will constrain the composition of pre-solar cometary grains and possibly the dynamics of the protosolar nebula. New measurements of D/H in Giant Planets, similarly constraining the composition of proto-planetary ices, will be obtained. The D/H and other isotopic ratios, diagnostic of Mars' atmosphere evolution, will be accurately measured in H 2 O and CO. The role of water vapour in Mars' atmospheric chemistry will be studied by monitoring vertical profiles of H 2 O and HDO and by searching for several other species (and CO and H 2 O isotopes). A detailed study of the source of water in the upper atmosphere of the Giant Planets and Titan will be performed. By monitoring the water abundance, vertical profile, and input fluxes in the various objects, and when possible with the help of mapping observations, we will discriminate between the possible sources of water in the Outer Planets (interplanetary dust particles, cometary impacts, and local sources). In addition to these inter-connected objectives, serendipitous searches may further enhance our knowledge of the composition of planetary and cometary atmospheres. For further details see:

0͒ band of the 16 O 18 O, 16 O 17 O, 18 O 2 , 17 O 18 O, and 17 O 2 isotopomersof oxygen. The weak magnetic dipole transitions around 760 nm were observed using cavity-ring-down absorption spectroscopy. The positions of over 340 lines are presented together with ͑re-͒ analyses of the rotational constants. We discuss the importance of these data in view of tests of the symmetrization postulate in 16 O 2 and present a sensitivity scale of 13 orders of magnitude that could be practical for future test experiments.

In a high-resolution laser spectroscopic study, using a tunable Fourier-transform limited light source in the extreme ultraviolet, the b 1 ⌸ u excited valence state of molecular nitrogen is reinvestigated for vibrational levels vϭ1, 4, 5, and 6. From line broadening of individual rotational levels excited state lifetimes were determined: (vϭ1) ϭ1.1Ϯ0.3 ns, (vϭ4) ϭ18Ϯ1 ps, (vϭ5) ϭ205Ϯ25 ps, and (vϭ6) ϭ350Ϯ75 ps. Additionally, the lifetime of the o 3 1 ⌸ u , vϭ0 Rydberg state was determined: ϭ240Ϯ50 ps. For the b 1 ⌸ u , vϭ1 state improved rotational constants were determined.