Electromagnetic wave penetration of reentry plasma sheaths

Methods to enable electro mag netic waves to propagate t hroug h t h e sheath of pla s ma created by a high s peed ve hicle ree n Le rin g a planeta ry at mos phere are reviewed and compa red. Attention is p a id to the possibi lit ies of e mployin g ve ry h igh frequency waves, low frequ ency waves, .of creatin g magneto-ioui c wave modes by imposin g static magn c tic fi elds, a nd of modlflll1g t he plasma by chemICal scedJI1~ an d ae rody nam ic effects. No ne of t he tec hniques are w It ho u t malor ltml tatIO ns and cons ldc rable cxperimen tal st udi es are st ill r equ ired to es tablish thcir feas ibi lity.